Thanks very much for the reply and for replying so quickly. If it's a windows problem I suppose I can format the drive and do a full install of windows, there isn't really much on the machine. But, I investigated some more and looked at the Event Viewer, so if it's any help to anyone, it has two errors, the second of which is interesting, and an information item -
Information
Product: Vodafone Mobile Connect -- Installation operation failed.
0000: 7b 39 36 42 35 31 43 30 {96B51C0
0008: 42 2d 44 33 42 45 2d 34 B-D3BE-4
0010: 44 46 33 2d 39 35 39 43 DF3-959C
0018: 2d 32 38 42 32 32 43 31 -28B22C1
0020: 30 43 46 42 42 7d 0CFBB}
-----------------------------------------------------------------------
Error
Product: Vodafone Mobile Connect -- Error 1714.The older version of
Vodafone Mobile Connect cannot be removed. Contact your technical support
group. System Error 1610.
0000: 7b 39 36 42 35 31 43 30 {96B51C0
0008: 42 2d 44 33 42 45 2d 34 B-D3BE-4
0010: 44 46 33 2d 39 35 39 43 DF3-959C
0018: 2d 32 38 42 32 32 43 31 -28B22C1
0020: 30 43 46 42 42 7d 0CFBB}
------------------------------------------------------------------------
Error
Unexpected or missing value (name: 'PackageName', value: '') in key
'HKLM\Software\Classes\Installer\Products\D3610C7F8DC9F5F4AB8CE3540A00A0FF\SourceList'
- and as a last attempt I created an entry for 'PackageName' in that registry key. Running the installation then lets me browse for a .msi installation package, but it claims the Vodafone installation msi I found in 'Application Data/Temp' is invalid. Maybe it wants to just delete one and I could just direct it to a copy of something else, as the old installation msi is inside its .exe. Must say this is beyond what I understand and I'm just making a last attempt to possibly avoid having to install windows.
Thanks very much for any thoughts or help.